RGBA Texture as an Alpha/Mask like in photoshop (Question)

Hi, hope you guys are doing great today. Can someone teach/show me how to make an RGBA texture as an Alpha/Mask of other texture in the Patch Editor like in Photoshop? Like the setup and what nodes to connect with. I’m quite lost in the logic and feels like I’m missing something that i feel like it’s so obvious but somehow i can’t see it. Thanks!

There are a few ways to do it, and it mostly depends on the format of your mask texture. You might have a grayscale mask, an alpha mask, or a full color mask.

  • If it’s grayscale, you can use any of the RGB channels and the result will be the same (I usually do swizzle x). This is the way photoshop handles masks.
  • If it’s an alpha mask, take the alpha channel.
  • If you have a full color image that you want to use as a mask (probably least common), you can use the luminance patch to convert into a single channel and use that as the mask.
  • One neat method for combining multiple masks in a single image is called channel packing (this is how ORM textures are formatted). You can convert 3 grayscale masks into red, blue, and green. Then you can grab each channel individually and get a different mask!

Once you have the correct channel isolated, you can pack it together with an RGB signal. I’m using a shortcut method here. Notice that the pack is set to vector 2 type, but it actually packs 4 total channels together. RGB is in the top slot and alpha is in the bottom. You could also manually pack all 4 channels in a vector 4, if you need.

Here’s the project, I hope it helps!

spark-alpha-pack-v95.arprojpkg (146.4 KB)